diff --git a/lib/CodeGen/MachineBlockFrequency.cpp b/lib/CodeGen/MachineBlockFrequency.cpp
index 893a320..0a77bdd 100644
--- a/lib/CodeGen/MachineBlockFrequency.cpp
+++ b/lib/CodeGen/MachineBlockFrequency.cpp
@@ -41,6 +41,7 @@
 void MachineBlockFrequency::getAnalysisUsage(AnalysisUsage &AU) const {
   AU.addRequired<MachineBranchProbabilityInfo>();
   AU.setPreservesAll();
+  MachineFunctionPass::getAnalysisUsage(AU);
 }
 
 bool MachineBlockFrequency::runOnMachineFunction(MachineFunction &F) {